Inside micrometer gauge



Oct. 20, 1925.

H. VOLIS v INSIDE MICROMETER GAUGE Filed Aug. 2 1924 A/W WIZZVENTOR.

g ATTORNl-IY.

Patented Oct. 20, 1925.

UNITED STATES PATENT OFFICE.

HARRY VOLIS, 013 DETROIT, MICHIGAN, ASSIGNOR T VOLIS PRECISION TOOL COM-IPANY, OF DETROIT, MICHIGAN A CORPORATION OF MICHIGAN.

INSIDE. MICROMETER GAUGE.

Application filed August 21, 1924. Serial No. 733,314.

To all whom it may concern:

Be it known that I, HARRY VOLlS, a citizen of the United States, andresiding at Detroit, in the county of lVayne and State of Michigan, haveinvented a new and Improved Inside Micrometer Gauge, of which thefollowing is a specification.

This invention relates to means for accurately determining the diametersof holes in and bores of metal bodies and the object of this inventionis to produce an instrument of this character which can be correctlyadjusted and which, after it becomes worn, can be readily and correctlyreadjusted.

A further object of this invention is t produce an instrument of thischaracter which can be readily corrected should its operative surfacesget out of alinement.

This invention consists in a body having longitudinal slots and bladesslidably mounted therein and provided with inner edges which areinclined in the same directio-n, a pair of expanders engaging saidinclined edges, means tomove said expanders to cause the blades to slideout radially, and means to move one of said expanders relative to theother so as to cause the adjacent ends of the blades to move outwardlyor inwardly while their opposite ends are sub stantially at rest so asto eliminate any taper there may be in the operative portion of theinstrument and to bring the operating sur faces of the blades intoparallellism.

It further consists in an instrument of this character embodyinganindicator and an operating member to move the expanders relative tothe blades and provided with a threaded portion engaging a threaded memher on the body, the indicator and body being graduated to indicate theexact diameter of the outer surface of the testing blades, the indicatorand operating member being relatively movable to permit accurateadjustment of the instrument for-diameter.

It further consists of the details of con- .struction illustrated in theaccompanying drawing and particularly pointed out in the claims.

In the drawing, Fig. 1 is a plan of this improved inside micrometergauge. Fig. 2 is a longitudinal section thereof. Figs. 8 and 4 aresections on the lines 3- 3 and 4- & of Fig. 2,

Similar reference characters refer to like parts throughout the severalviews.

The body of this instrument, that is, that portion which is rigid whenassembled, comprises a head 1, a cap 2 secured to the head by means ofscrews 3, a handle 4. screwed onto the neck 5 of the head and a tubularmember 6 screwed into this neck. Except for difficulties in manufacture,the head and tubular member might be integral.

The head 1 is radially and longitudinally slotted to receive theradially sliable blades 8 which are internally grooved to receive thesprings 9 whose ends extend into the circular groove 10 in the cap andbeneath the circular shoulder 11 of the head. Pins 12 position thesesprings. The blades have inclined inner edges 14 and 15 which are at Iprefer to form the expanders of hard steel and the bushings of bronze toavoid wear and friction respectively. The ex- .panders have flatinclined surfaces at the same angle as the edges 14 and 15 of theblades. Outward movements of the expanders are resisted by the springs 9but are effected through the ball bearing 27 and devices to be explainedlater on; These expanders do not rotate in the head, being prevented bythe engagement of their flat surfaces 13 with the ends of the blades.

The pressure of the bearing 27 on the inner end of the bushing istransmitted in art to the sleeve 22 and by that to the bus ring 23. Thesleeve 22'is slidable on the shaft 16 but cannot rotate thereon be causeof the screw 28 in this shaft extending into the slot 29 in the sleeve.The angles of the expanders being the same, both ends of the blades 8will move outwardly the same distance for equal longitudinal movementsof the expanders. But should the outer ends of the blades extend outwarda greater or less distance than the inner ends, which is the case whenthe blades become worn, then the screw 17 is releasedand the shaft 16and the sleeve 22 turned relative to the bushing 23 to move the expander2i inward or outward until the operating sur faces of the blades are inexact parallelism.

The end 31- of the tubular member 5 is formed with very i-inifornilpitched and quite fine threads, preferably forty per inch and anoperating sleeve 32 is externally threaded to fit therein. The inner endor" the sleeve engages the bearing 27 so that the enpanders are movedoutwardly when this sleeve is turneiil in one direction and are movedinwardly through the pressure of the springs 9 when the sleeve 32 isturned in the opposite direction. It the angle of the operating surfacesof the eX panders to the axis of the shaft 16 is thirty degrees and thethreads on the sleeve are forty per inch, one rotation of the sleevewill cause the blades to move outwardly .0125 inch and measurements of.0001 of an inch are easily determined.

I. prefer to secure an indicating shell or indicator 3 1 to theoperating sleeve 32 and to graduate itstapering outer end 35,- and tograduate the middle portion of the tubularineniber 6 toco-operate' withthe graduations on the indicator 34. Openings 36 may be formed in thehandle l through which these graduations may be seen, and when Verniergraduations are employed, variations of .0001 inch in the workingdiameter of this instrument are provided for.

The blades are first positioned for a predetermined measurement. Theindicator 3-1; is then accurately positioned on the tubular member 6 sothat their nations indicate the desired diameter. The screw 38 is thenforced, in to press the ball 39 against the interior surface of thesliellwliicli locks the indicator to the operating sleeve. Thisoperating sleeve is mounted on the tubular member 6 and is bore-d to itthe shah. l6 which is therefore suppc'irted thereby.

A collar ll is firmly held in the handle l by being a press-fit. Anoperating connector 4; is rotatably mounted in this collar and its innerend comprises a pair of fingers 18 which extend into notches in theadjacent end of the operating sleeve A locking button ail screws ontothe outer end 1-6 oi this connector and an operating collar is slidablybut non-rotatably attached to the connector by the pin 47. A springwasher 48 is placed between the button i l and the shoulder 49 of thecollar The inner end of the operating collar .15 and the shoulder 50 ofthe connector 42 engage the stationary collar ll. A. screw 52 carried bythe operating collar 45 enters the groove 53 in the locking but-ton andprevents it from getting lost but permit-s suflicient longitudinalmovement-0f the but-ten.

VVhe'n the looking button is screwed down onto the threaded end d6 ofthe connector 12. the spring washer l8 causes the operating collar 45and the shoulder 50 on the connector to engage the stationary collar -llof the handle with such for-ceas to prevent movement betweenthem. Thisalso locks the operating sleeve and therefore substantially locks theblades.

When the button lei is turned back to release the operating collar thismay be freely turned to turn the connector 41-2 and the sleeve 32 andthus cause the expanders to move longitudinally of the blades.

The threads between the portion 31 01 the sleeve 6 and the sleeve 32must be accurately uniform in pitch and the angle oi the inclines ofboth of the expanders m: be the same and must be laid out to cooperatewith the gradu'ations of the indicator and the tubularmember 6. Theseare matters well within the domain of skilled e 'ineers. The details ofconstruction and proportions and sizes of the parts may also be variedby those skilled in the art without departing from the spirit ot-myinvention as set forth in the following claims.

I claim 1. in a gauge, the combination of a hollow cylindrical bodyhaving a radia lslot, a central shaft in the body, expanilers slidalnymounted on the shaft and havii'ig sur faces inclined to the axis oi saidshaft, a blade mounted in the slot in engagement with said inclinedsurfaces on the expanders. means toslide the expander-s along the shaftin onedirection as a unit to force the blade outwardly, and means tovary the distance between said expan'ders.

2. In a gauge, the combinwion of a hob low cylindrical body having aadial slot. a central shaft in the-- body. expandcrs slida bly mountedon the shalt and having surfaces inclined to the axis of said shalt, ablade inountedin the slot in engagement with said inclined surfaces onthe expanders, means to-slide the estpauders along'the shaft in onedirection as a unit to tlo'rce the blade outwardly, resilient means todraw theblade into the slot and to slide the expander-s in the oppositedirection. and means to vary the distance between said expanders.

3. In a gauge, the combination or a hellow cylindrical body havingradial slots. expanders movable longitudinally oi the body and havingoperating surfaces inclined to the axis oi? said shatt. blades mountedin the slots contacting with the inclined sun faces on the expandcrs. atubular e:-:tension. on the body having a threaded end. an operatingmember operatively engaging said threaded end and the expanders to forcethe expander-s along the shaft in one direction as a unit to cause theblades to move outwardly, and means to vary the distance between saidexpanders.

kl a

4:. In a gauge, the combination of a hollow cylindrical body havingradial slots, a central shaft mounted in the body, eX- panders slidablymounted on the shaft and having surfaces inclined to the axis of saidshaft, blades mounted in the slots and provided with inc-lined surfacesin engagement with the inclined surfaces on the expanders, a tubularextension on the body having an internally threaded end, an operatingsleeve engaging said threaded end and the expanders to force theexpanders along the shaft in one direction as a unit to cause the bladesto move outwardly, and means to vary the distance between saidexpanders.

5. In a gauge, the combination of a hollow cylindrical body havingradial slots, a central shaft mounted in the body, expanders slidablymounted on the shaft and having operating surfaces inclined to the axisof said shaft, blades mounted in the slots in engagement with theinclined surfaces on the expanders, a tubular extension on the bodyhaving an internally threaded end, and an operating sleeve engaging saidthreaded end and the expanders to force the expanders along the shaft onone direction. as a unit to cause the blades to move outwardly.

6. In a gauge, the combination of a hollow cylindrical body havingradial. slots, a cent :11 shaft mounted in the body, expanders slidablymounted on the shaft and having surfaces inclined to the axis of saidshaft, blades mounted in the slots in engagement with the inclinedsurfaces on the expanders, a tubular extension on the body having aninternally threaded end, an operating sleeve engaging said threaded endand the expanders to force the expanders along the shaft in onedirection as a unit to cause the blades to move outwardly, means to varythe distance between said expanders, a graduated indicatdr adjustablysecured to the operating sleeve, and a cylindrical handle attached tothe body and provided with openings through which the graduations on theindicator may be observed.

'7. In a gauge, the combination of a hollow cylindrical body havingradial slots, a central shaft mounted in the body, expanders slidablymounted on the shaft and having surfaces inclined to the axis of saidshaft, blades mounted in the slots in engagement with the inclinedsurfaces on the expandcrs, a tubular extension on the body having aninternally threaded end, an operating sleeve engaging said. threaded endand the expanders to force the expanders along the shaft in onedirection as a unit to cause the blades to move outwardly, means to varythe distance between said expanders, a

graduated cylindrical indicator adjustably secured to the operatingsleeve, a cylindrical handle attached to the body and provided withopeningsthrough which the graduations 011 the indicator may be observed,and an operating collar at the end of the handle connected to theoperating sleeve, said collar being rotatable relative to the handle andslidably connected to said operating sleeve.

8. In a gauge, the combination of a hollow cylindrical body havingradial slots, a central shaft mounted in the body, expanders slidablymounted on the shaft and having surfaces inclined to the axis of saidshaft, blades mounted inthe slots and provided with surfaces inengagement with the inclined surfaces on the expanders, a tubularextension on the body having an internally threaded end, an operatingsleeve engaging said threaded end and the expanders to force theexpanders'along the shaft in one direction as a unit to cause the bladesto move outwardly, means to vary the distance between said expanders, agraduated indicator adjustably secured to the operating sleeve, acylindrical handle at tached to the body and provided with open ingsthrough which the graduations on the indicator may be observed, anoperating collar at the end of the handle connected to the operatingsleeve, said collar being rotatable relative to the handle and slidablyconnected to said operating sleeve, and means to lock the collar.

9. In a gauge, the combination of a. hollow body having an even numberof radial slots, blades mounted in said body and having their inneredges formed with surfaces inclined to the axis of said shaft, expandersmovable in said body and having surfaces inclined in the same directionin engagement with the inclined surfaces on the blades, a screw to forcethe expanders to more in one direction, and springs in engagement withthe blades to move the expanders in the opposite direction. 10. In agauge, the combination of a hollow body having an even number of radialslots, blades mounted in said body and having their inner edges formedwith surfaces inclined to the axis of said shaft, expanders movable insaid body and having surfaces inclined in the same direction inengagement with the inclined surfaces on the blades, a screw to forcethe expanders to move in one direction, and springs to move theexpanders in the opposite direction, said blades being longitudinallygrooved in their inner edges and said springs being seated in thegrooves and engaging the body with their ends.

HARRY VOLIS.

